I'd look for brands you like then like mortgages go with whatever deal suits you best.
Brands I like (Brass or Steel cased)
Blazer
Sellier & Bellot
Federal
Hornady (less common here)
Barnaul (steel if you are ok with that)
I don't recommend Aluminum cases...It can cause you trouble unless you are careful. I had this happen and will forever avoid it from now on. occurred in a Semi-carbine that specifically said not to use aluminium ammo into, so I decided to use the rest of the ammo in pistols only the same thing happened in a glock 17. Common factor was a Amend 2 plastic glock magazine that seems to have a weaker spring....Still i'd rather brass or steel that wouldn't do what is pictured below.